for free to everyone around the world, they're going to turn education, high-quality education, from a privilege to a basic human right, so that anyone, no matter their social, economic or family circumstances, has access to the best education. >> reporter: those lofty goals-- the experience of teaching thousands of students and the possibility of future profits-- are what got these courses going. professors from top universities are signing up, even though they are not paid by the providers. eventually, universities may share revenues they receive-- when there are revenues-- with the professors. and those star professors have inspired intense student interest in the courses, says coursera's other co-founder, andrew ng. >> most people today will never have access to a princeton, stanford, cal tech class. but now, if you wake up tomorrow morning and you decide you want to take a cal tech class, you can. you can just sign up for one, and it's free. >> reporter: math teacher salman khan started providing free online classes in 2010 out of his house, arguing that new approaches to teachi